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MIPS Technologies claimed that because an exception handler could be created to emulate the function of unaligned loads and stores in software with many other instructions Lexra's processors infringed the patent.

One interesting problem with the patent system is that one institution, the patent and trademark office, determines whether a patent is valid but a different institution, the courts, determine whether one infringes. It is entirely possible for the two institutions to interpret a patent differently and for either a non-infringer to be wrongly convicted or an infringer to get away with their crime. The case of MIPS Technologies v Lexra was ultimately settled out of court and the request for reexamination of the patent was dropped. To this day there is no precedent protecting the MIPS-I instruction set from being cloned. It is interesting to watch as the Chinese company, BLX, makes and sells MIPS instruction set processors in China, presumably without paying anything to MIPS Technologies for the privilege of not being sued.

Prudent high tech companies study their competitors' patent portfolios, and Lexra was no exception. Lexra was well aware of the patent on unaligned loads and stores that was owned by Silicon Graphics and later by MIPS Technologies. To avoid infringing, Lexra chose not to implement unaligned loads and stores in its processor design. To settle a small trademark dispute between the companies, Lexra agreed to always state in its documentation and press announcements that it implemented "the MIPS-I instruction set except for unaligned loads and stores". MIPS Technologies agreed to that settlement, apparently acknowledging that Lexra did not execute unaligned loads and stores. If a Lexra processor encountered an unaligned load or store instruction in the program that it was executing then it did the same thing that it would do for any other invalid opcode, it took a reserved instruction exception.

In the big law suit between MIPS Technologies and Lexra, MIPS Technologies claimed that because an exception handler could be created to emulate the function of unaligned loads and stores in software with many other instructions Lexra's processors infringed the patent. Upon learning of this broad interpretation of the patent, Lexra requested that the US Patent and Trademark office reexamine whether the patent was novel when granted. Almost every microprocessor in the world can emulate the functionality of unaligned loads and stores in software. MIPS Technologies did not invent that. By any reasonable interpretation of the MIPS Technologies' patent, Lexra did not infringe.

In the court case MIPS Technologies' lawyers stalled at every opportunity possible in the hope that Lexra would run out of money, and ultimately they succeeded. Because MIPS Technologies started the game with far more money than Lexra, they outlasted and Lexra was forced into a settlement. Though MIPS Technologies was suing Lexra, the settlement agreement involved MIPS paying Lexra money. The benefit that MIPS Technologies got in exchange was that Lexra exited the SIP business and then failed one year later in an attempt to establish itself as a communications chip company.


"We don't want them to further discuss it," said Cisco spokesman John Noh. "This is about protecting our intellectual property."

"It is especially regretful, and indefensible, that the Black Hat Conference organizers have given Mr. Lynn a platform to publicly disseminate the information he illegally obtained," the company said in a statement. "We appreciate the cooperation we have received from ISS in this matter. We are working with ISS to continue our joint research in the area of security vulnerabilities."

Cisco, ISS file suit against rogue researcher


Intellectual property rights issues have plagued WRAP. Three different parties have filed for patents on WRAP. These intellectual property issues caused the IEEE to introduce CCMP into the 802.11i standard and make WRAP an optional component of RSN (Robust Secure Network).

What is WRAP (Wireless Robust Authenticated Protocol)?

WRAP (Wireless Robust Authenticated Protocol) is an encryption protocol in the 802.11i standard. WRAP is based upon the Offset Codebook (OCB) mode of AES. WRAP is being Replaced with CCMP

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Page last modified on July 28, 2005, at 04:43 PM